By Erik Kirschbaum
BERLIN (Reuters) - Germany's 16 states launched a battle on Tuesday to ban the far-right National Democratic Party (NPD) after the federal government failed spectacularly a decade ago to outlaw a party its critics say shows an affinity for Hitler's Nazis.
Fearing another court defeat, Chancellor Angela Merkel's government opted not to formally back the petition to the Constitutional Court to ban the NPD, which the domestic intelligence service has called "racist, anti-Semitic and revisionist".
Banning a political group is difficult in Germany, still haunted by memories of Nazi and communist regimes which crushed dissent. A previous attempt by the federal government in 2003 to ban the NPD failed, causing deep embarrassment.
Germany's large ethnic Turkish community, the Central Council of Jews and Central Council of Sinti and Roma have criticized the government for failing to join the states in their petition, saying it was shirking its responsibility.
Calls for another attempt to ban the party grew after it emerged in 2011 that a neo-Nazi cell had gone on a racist killing spree over a decade. The NPD denied any links to that.
The states quote from an NPD pamphlet in their petition to the Constitutional Court in Karlsruhe: "You are either a German from birth or not a German."
"An African or Asian ... can never become a German because giving them a piece of paper will not change their biological genetic makeup. People from other races will remain foreign bodies no matter how long they live in Germany."
The NPD, which was founded in 1964 and won just 1.3 percent of the vote in September's election, has no seats in the federal parliament but has cleared the five percent threshold to win representation in regional states.
"There is a recognizable affinity" between the NPD and Hitler's Nazi party that justifies a ban, the states said in their petition to the court. They based their case on the NPD's "degrading racism".
The states want to ban the NPD and prevent it receiving the taxpayer funding for which parties are eligible. The NPD got 1.4 million euros ($1.9 million) in 2012.
More radical than populist anti-immigrant parties in France, Britain and the Netherlands, the NPD campaigns for full employment, greater national sovereignty in defense and foreign affairs and an end to immigration.
"It would have been better from a political point of view if the federal government had joined with the states but from a legal point of view that won't have any impact," said Carsten Koschmieder, political scientist at Berlin's Free University.
"No one knows if it'll succeed this time around. The NPD's clear affinity for the Nazi party can easily be proven. But the difficult question will be if the NPD is actively working to undermine Germany's principles of human rights and freedoms."
Opponents of the drive to ban the NPD say it would give the party free publicity. They also fear outlawing the party would push it underground and make it more difficult to monitor.
The 2003 attempt to ban the NPD collapsed because its case relied heavily on paid informants from inside the NPD. Merkel has said she did not want to risk failure a second time round as that could help legitimize the NPD in the eyes of some voters.
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(Editing by Ralph Boulton)